arch/powerpc/platforms/cell/io-workarounds.c - maze/linux - Git at Google

 /*
  *  Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
  *		       IBM, Corp.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
 #undef DEBUG

 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/pci.h>
 #include <asm/io.h>
 #include <asm/machdep.h>
 #include <asm/pci-bridge.h>
 #include <asm/ppc-pci.h>


 #define SPIDER_PCI_REG_BASE		0xd000
 #define SPIDER_PCI_VCI_CNTL_STAT	0x0110
 #define SPIDER_PCI_DUMMY_READ		0x0810
 #define SPIDER_PCI_DUMMY_READ_BASE	0x0814

 /* Undefine that to re-enable bogus prefetch
  *
  * Without that workaround, the chip will do bogus prefetch past
  * page boundary from system memory. This setting will disable that,
  * though the documentation is unclear as to the consequences of doing
  * so, either purely performances, or possible misbehaviour... It's not
  * clear wether the chip can handle unaligned accesses at all without
  * prefetching enabled.
  *
  * For now, things appear to be behaving properly with that prefetching
  * disabled and IDE, possibly because IDE isn't doing any unaligned
  * access.
  */
 #define SPIDER_DISABLE_PREFETCH

 #define MAX_SPIDERS	3

 static struct spider_pci_bus {
 	void __iomem	*regs;
 	unsigned long	mmio_start;
 	unsigned long	mmio_end;
 	unsigned long	pio_vstart;
 	unsigned long	pio_vend;
 } spider_pci_busses[MAX_SPIDERS];
 static int spider_pci_count;

 static struct spider_pci_bus *spider_pci_find(unsigned long vaddr,
 					      unsigned long paddr)
 {
 	int i;

 	for (i = 0; i < spider_pci_count; i++) {
 		struct spider_pci_bus *bus = &spider_pci_busses[i];
 		if (paddr && paddr >= bus->mmio_start && paddr < bus->mmio_end)
 			return bus;
 		if (vaddr && vaddr >= bus->pio_vstart && vaddr < bus->pio_vend)
 			return bus;
 	}
 	return NULL;
 }

 static void spider_io_flush(const volatile void __iomem *addr)
 {
 	struct spider_pci_bus *bus;
 	int token;

 	/* Get platform token (set by ioremap) from address */
 	token = PCI_GET_ADDR_TOKEN(addr);

 	/* Fast path if we have a non-0 token, it indicates which bus we
 	 * are on.
 	 *
 	 * If the token is 0, that means either that the ioremap was done
 	 * before we initialized this layer, or it's a PIO operation. We
 	 * fallback to a low path in this case. Hopefully, internal devices
 	 * which are ioremap'ed early should use in_XX/out_XX functions
 	 * instead of the PCI ones and thus not suffer from the slowdown.
 	 *
 	 * Also note that currently, the workaround will not work for areas
 	 * that are not mapped with PTEs (bolted in the hash table). This
 	 * is the case for ioremaps done very early at boot (before
 	 * mem_init_done) and includes the mapping of the ISA IO space.
 	 *
 	 * Fortunately, none of the affected devices is expected to do DMA
 	 * and thus there should be no problem in practice.
 	 *
 	 * In order to improve performances, we only do the PTE search for
 	 * addresses falling in the PHB IO space area. That means it will
 	 * not work for hotplug'ed PHBs but those don't exist with Spider.
 	 */
 	if (token && token <= spider_pci_count)
 		bus = &spider_pci_busses[token - 1];
 	else {
 		unsigned long vaddr, paddr;
 		pte_t *ptep;

 		/* Fixup physical address */
 		vaddr = (unsigned long)PCI_FIX_ADDR(addr);

 		/* Check if it's in allowed range for  PIO */
 		if (vaddr < PHBS_IO_BASE || vaddr >= IMALLOC_BASE)
 			return;

 		/* Try to find a PTE. If not, clear the paddr, we'll do
 		 * a vaddr only lookup (PIO only)
 		 */
 		ptep = find_linux_pte(init_mm.pgd, vaddr);
 		if (ptep == NULL)
 			paddr = 0;
 		else
 			paddr = pte_pfn(*ptep) << PAGE_SHIFT;

 		bus = spider_pci_find(vaddr, paddr);
 		if (bus == NULL)
 			return;
 	}

 	/* Now do the workaround
 	 */
 	(void)in_be32(bus->regs + SPIDER_PCI_DUMMY_READ);
 }

 static u8 spider_readb(const volatile void __iomem *addr)
 {
 	u8 val = __do_readb(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u16 spider_readw(const volatile void __iomem *addr)
 {
 	u16 val = __do_readw(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u32 spider_readl(const volatile void __iomem *addr)
 {
 	u32 val = __do_readl(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u64 spider_readq(const volatile void __iomem *addr)
 {
 	u64 val = __do_readq(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u16 spider_readw_be(const volatile void __iomem *addr)
 {
 	u16 val = __do_readw_be(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u32 spider_readl_be(const volatile void __iomem *addr)
 {
 	u32 val = __do_readl_be(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static u64 spider_readq_be(const volatile void __iomem *addr)
 {
 	u64 val = __do_readq_be(addr);
 	spider_io_flush(addr);
 	return val;
 }

 static void spider_readsb(const volatile void __iomem *addr, void *buf,
 			  unsigned long count)
 {
 	__do_readsb(addr, buf, count);
 	spider_io_flush(addr);
 }

 static void spider_readsw(const volatile void __iomem *addr, void *buf,
 			  unsigned long count)
 {
 	__do_readsw(addr, buf, count);
 	spider_io_flush(addr);
 }

 static void spider_readsl(const volatile void __iomem *addr, void *buf,
 			  unsigned long count)
 {
 	__do_readsl(addr, buf, count);
 	spider_io_flush(addr);
 }

 static void spider_memcpy_fromio(void *dest, const volatile void __iomem *src,
 				 unsigned long n)
 {
 	__do_memcpy_fromio(dest, src, n);
 	spider_io_flush(src);
 }


 static void __iomem * spider_ioremap(unsigned long addr, unsigned long size,
 				     unsigned long flags)
 {
 	struct spider_pci_bus *bus;
 	void __iomem *res = __ioremap(addr, size, flags);
 	int busno;

 	pr_debug("spider_ioremap(0x%lx, 0x%lx, 0x%lx) -> 0x%p\n",
 		 addr, size, flags, res);

 	bus = spider_pci_find(0, addr);
 	if (bus != NULL) {
 		busno = bus - spider_pci_busses;
 		pr_debug(" found bus %d, setting token\n", busno);
 		PCI_SET_ADDR_TOKEN(res, busno + 1);
 	}
 	pr_debug(" result=0x%p\n", res);

 	return res;
 }

 static void __init spider_pci_setup_chip(struct spider_pci_bus *bus)
 {
 #ifdef SPIDER_DISABLE_PREFETCH
 	u32 val = in_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT);
 	pr_debug(" PVCI_Control_Status was 0x%08x\n", val);
 	out_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT, val | 0x8);
 #endif

 	/* Configure the dummy address for the workaround */
 	out_be32(bus->regs + SPIDER_PCI_DUMMY_READ_BASE, 0x80000000);
 }

 static void __init spider_pci_add_one(struct pci_controller *phb)
 {
 	struct spider_pci_bus *bus = &spider_pci_busses[spider_pci_count];
 	struct device_node *np = phb->arch_data;
 	struct resource rsrc;
 	void __iomem *regs;

 	if (spider_pci_count >= MAX_SPIDERS) {
 		printk(KERN_ERR "Too many spider bridges, workarounds"
 		       " disabled for %s\n", np->full_name);
 		return;
 	}

 	/* Get the registers for the beast */
 	if (of_address_to_resource(np, 0, &rsrc)) {
 		printk(KERN_ERR "Failed to get registers for spider %s"
 		       " workarounds disabled\n", np->full_name);
 		return;
 	}

 	/* Mask out some useless bits in there to get to the base of the
 	 * spider chip
 	 */
 	rsrc.start &= ~0xfffffffful;

 	/* Map them */
 	regs = ioremap(rsrc.start + SPIDER_PCI_REG_BASE, 0x1000);
 	if (regs == NULL) {
 		printk(KERN_ERR "Failed to map registers for spider %s"
 		       " workarounds disabled\n", np->full_name);
 		return;
 	}

 	spider_pci_count++;

 	/* We assume spiders only have one MMIO resource */
 	bus->mmio_start = phb->mem_resources[0].start;
 	bus->mmio_end = phb->mem_resources[0].end + 1;

 	bus->pio_vstart = (unsigned long)phb->io_base_virt;
 	bus->pio_vend = bus->pio_vstart + phb->pci_io_size;

 	bus->regs = regs;

 	printk(KERN_INFO "PCI: Spider MMIO workaround for %s\n",np->full_name);

 	pr_debug(" mmio (P) = 0x%016lx..0x%016lx\n",
 		 bus->mmio_start, bus->mmio_end);
 	pr_debug("  pio (V) = 0x%016lx..0x%016lx\n",
 		 bus->pio_vstart, bus->pio_vend);
 	pr_debug(" regs (P) = 0x%016lx (V) = 0x%p\n",
 		 rsrc.start + SPIDER_PCI_REG_BASE, bus->regs);

 	spider_pci_setup_chip(bus);
 }

 static struct ppc_pci_io __initdata spider_pci_io = {
 	.readb = spider_readb,
 	.readw = spider_readw,
 	.readl = spider_readl,
 	.readq = spider_readq,
 	.readw_be = spider_readw_be,
 	.readl_be = spider_readl_be,
 	.readq_be = spider_readq_be,
 	.readsb = spider_readsb,
 	.readsw = spider_readsw,
 	.readsl = spider_readsl,
 	.memcpy_fromio = spider_memcpy_fromio,
 };

 static int __init spider_pci_workaround_init(void)
 {
 	struct pci_controller *phb;

 	if (!machine_is(cell))
 		return 0;

 	/* Find spider bridges. We assume they have been all probed
 	 * in setup_arch(). If that was to change, we would need to
 	 * update this code to cope with dynamically added busses
 	 */
 	list_for_each_entry(phb, &hose_list, list_node) {
 		struct device_node *np = phb->arch_data;
 		const char *model = of_get_property(np, "model", NULL);

 		/* If no model property or name isn't exactly "pci", skip */
 		if (model == NULL || strcmp(np->name, "pci"))
 			continue;
 		/* If model is not "Spider", skip */
 		if (strcmp(model, "Spider"))
 			continue;
 		spider_pci_add_one(phb);
 	}

 	/* No Spider PCI found, exit */
 	if (spider_pci_count == 0)
 		return 0;

 	/* Setup IO callbacks. We only setup MMIO reads. PIO reads will
 	 * fallback to MMIO reads (though without a token, thus slower)
 	 */
 	ppc_pci_io = spider_pci_io;

 	/* Setup ioremap callback */
 	ppc_md.ioremap = spider_ioremap;

 	return 0;
 }
 arch_initcall(spider_pci_workaround_init);
	/*
	* Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
	* IBM, Corp.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/
	#undef DEBUG

	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/pci.h>
	#include <asm/io.h>
	#include <asm/machdep.h>
	#include <asm/pci-bridge.h>
	#include <asm/ppc-pci.h>


	#define SPIDER_PCI_REG_BASE 0xd000
	#define SPIDER_PCI_VCI_CNTL_STAT 0x0110
	#define SPIDER_PCI_DUMMY_READ 0x0810
	#define SPIDER_PCI_DUMMY_READ_BASE 0x0814

	/* Undefine that to re-enable bogus prefetch
	*
	* Without that workaround, the chip will do bogus prefetch past
	* page boundary from system memory. This setting will disable that,
	* though the documentation is unclear as to the consequences of doing
	* so, either purely performances, or possible misbehaviour... It's not
	* clear wether the chip can handle unaligned accesses at all without
	* prefetching enabled.
	*
	* For now, things appear to be behaving properly with that prefetching
	* disabled and IDE, possibly because IDE isn't doing any unaligned
	* access.
	*/
	#define SPIDER_DISABLE_PREFETCH

	#define MAX_SPIDERS 3

	static struct spider_pci_bus {
	void __iomem *regs;
	unsigned long mmio_start;
	unsigned long mmio_end;
	unsigned long pio_vstart;
	unsigned long pio_vend;
	} spider_pci_busses[MAX_SPIDERS];
	static int spider_pci_count;

	static struct spider_pci_bus *spider_pci_find(unsigned long vaddr,
	unsigned long paddr)
	{
	int i;

	for (i = 0; i < spider_pci_count; i++) {
	struct spider_pci_bus *bus = &spider_pci_busses[i];
	if (paddr && paddr >= bus->mmio_start && paddr < bus->mmio_end)
	return bus;
	if (vaddr && vaddr >= bus->pio_vstart && vaddr < bus->pio_vend)
	return bus;
	}
	return NULL;
	}

	static void spider_io_flush(const volatile void __iomem *addr)
	{
	struct spider_pci_bus *bus;
	int token;

	/* Get platform token (set by ioremap) from address */
	token = PCI_GET_ADDR_TOKEN(addr);

	/* Fast path if we have a non-0 token, it indicates which bus we
	* are on.
	*
	* If the token is 0, that means either that the ioremap was done
	* before we initialized this layer, or it's a PIO operation. We
	* fallback to a low path in this case. Hopefully, internal devices
	* which are ioremap'ed early should use in_XX/out_XX functions
	* instead of the PCI ones and thus not suffer from the slowdown.
	*
	* Also note that currently, the workaround will not work for areas
	* that are not mapped with PTEs (bolted in the hash table). This
	* is the case for ioremaps done very early at boot (before
	* mem_init_done) and includes the mapping of the ISA IO space.
	*
	* Fortunately, none of the affected devices is expected to do DMA
	* and thus there should be no problem in practice.
	*
	* In order to improve performances, we only do the PTE search for
	* addresses falling in the PHB IO space area. That means it will
	* not work for hotplug'ed PHBs but those don't exist with Spider.
	*/
	if (token && token <= spider_pci_count)
	bus = &spider_pci_busses[token - 1];
	else {
	unsigned long vaddr, paddr;
	pte_t *ptep;

	/* Fixup physical address */
	vaddr = (unsigned long)PCI_FIX_ADDR(addr);

	/* Check if it's in allowed range for PIO */
	if (vaddr < PHBS_IO_BASE \|\| vaddr >= IMALLOC_BASE)
	return;

	/* Try to find a PTE. If not, clear the paddr, we'll do
	* a vaddr only lookup (PIO only)
	*/
	ptep = find_linux_pte(init_mm.pgd, vaddr);
	if (ptep == NULL)
	paddr = 0;
	else
	paddr = pte_pfn(*ptep) << PAGE_SHIFT;

	bus = spider_pci_find(vaddr, paddr);
	if (bus == NULL)
	return;
	}

	/* Now do the workaround
	*/
	(void)in_be32(bus->regs + SPIDER_PCI_DUMMY_READ);
	}

	static u8 spider_readb(const volatile void __iomem *addr)
	{
	u8 val = __do_readb(addr);
	spider_io_flush(addr);
	return val;
	}

	static u16 spider_readw(const volatile void __iomem *addr)
	{
	u16 val = __do_readw(addr);
	spider_io_flush(addr);
	return val;
	}

	static u32 spider_readl(const volatile void __iomem *addr)
	{
	u32 val = __do_readl(addr);
	spider_io_flush(addr);
	return val;
	}

	static u64 spider_readq(const volatile void __iomem *addr)
	{
	u64 val = __do_readq(addr);
	spider_io_flush(addr);
	return val;
	}

	static u16 spider_readw_be(const volatile void __iomem *addr)
	{
	u16 val = __do_readw_be(addr);
	spider_io_flush(addr);
	return val;
	}

	static u32 spider_readl_be(const volatile void __iomem *addr)
	{
	u32 val = __do_readl_be(addr);
	spider_io_flush(addr);
	return val;
	}

	static u64 spider_readq_be(const volatile void __iomem *addr)
	{
	u64 val = __do_readq_be(addr);
	spider_io_flush(addr);
	return val;
	}

	static void spider_readsb(const volatile void __iomem addr, void buf,
	unsigned long count)
	{
	__do_readsb(addr, buf, count);
	spider_io_flush(addr);
	}

	static void spider_readsw(const volatile void __iomem addr, void buf,
	unsigned long count)
	{
	__do_readsw(addr, buf, count);
	spider_io_flush(addr);
	}

	static void spider_readsl(const volatile void __iomem addr, void buf,
	unsigned long count)
	{
	__do_readsl(addr, buf, count);
	spider_io_flush(addr);
	}

	static void spider_memcpy_fromio(void dest, const volatile void __iomem src,
	unsigned long n)
	{
	__do_memcpy_fromio(dest, src, n);
	spider_io_flush(src);
	}


	static void __iomem * spider_ioremap(unsigned long addr, unsigned long size,
	unsigned long flags)
	{
	struct spider_pci_bus *bus;
	void __iomem *res = __ioremap(addr, size, flags);
	int busno;

	pr_debug("spider_ioremap(0x%lx, 0x%lx, 0x%lx) -> 0x%p\n",
	addr, size, flags, res);

	bus = spider_pci_find(0, addr);
	if (bus != NULL) {
	busno = bus - spider_pci_busses;
	pr_debug(" found bus %d, setting token\n", busno);
	PCI_SET_ADDR_TOKEN(res, busno + 1);
	}
	pr_debug(" result=0x%p\n", res);

	return res;
	}

	static void __init spider_pci_setup_chip(struct spider_pci_bus *bus)
	{
	#ifdef SPIDER_DISABLE_PREFETCH
	u32 val = in_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT);
	pr_debug(" PVCI_Control_Status was 0x%08x\n", val);
	out_be32(bus->regs + SPIDER_PCI_VCI_CNTL_STAT, val \| 0x8);
	#endif

	/* Configure the dummy address for the workaround */
	out_be32(bus->regs + SPIDER_PCI_DUMMY_READ_BASE, 0x80000000);
	}

	static void __init spider_pci_add_one(struct pci_controller *phb)
	{
	struct spider_pci_bus *bus = &spider_pci_busses[spider_pci_count];
	struct device_node *np = phb->arch_data;
	struct resource rsrc;
	void __iomem *regs;

	if (spider_pci_count >= MAX_SPIDERS) {
	printk(KERN_ERR "Too many spider bridges, workarounds"
	" disabled for %s\n", np->full_name);
	return;
	}

	/* Get the registers for the beast */
	if (of_address_to_resource(np, 0, &rsrc)) {
	printk(KERN_ERR "Failed to get registers for spider %s"
	" workarounds disabled\n", np->full_name);
	return;
	}

	/* Mask out some useless bits in there to get to the base of the
	* spider chip
	*/
	rsrc.start &= ~0xfffffffful;

	/* Map them */
	regs = ioremap(rsrc.start + SPIDER_PCI_REG_BASE, 0x1000);
	if (regs == NULL) {
	printk(KERN_ERR "Failed to map registers for spider %s"
	" workarounds disabled\n", np->full_name);
	return;
	}

	spider_pci_count++;

	/* We assume spiders only have one MMIO resource */
	bus->mmio_start = phb->mem_resources[0].start;
	bus->mmio_end = phb->mem_resources[0].end + 1;

	bus->pio_vstart = (unsigned long)phb->io_base_virt;
	bus->pio_vend = bus->pio_vstart + phb->pci_io_size;

	bus->regs = regs;

	printk(KERN_INFO "PCI: Spider MMIO workaround for %s\n",np->full_name);

	pr_debug(" mmio (P) = 0x%016lx..0x%016lx\n",
	bus->mmio_start, bus->mmio_end);
	pr_debug(" pio (V) = 0x%016lx..0x%016lx\n",
	bus->pio_vstart, bus->pio_vend);
	pr_debug(" regs (P) = 0x%016lx (V) = 0x%p\n",
	rsrc.start + SPIDER_PCI_REG_BASE, bus->regs);

	spider_pci_setup_chip(bus);
	}

	static struct ppc_pci_io __initdata spider_pci_io = {
	.readb = spider_readb,
	.readw = spider_readw,
	.readl = spider_readl,
	.readq = spider_readq,
	.readw_be = spider_readw_be,
	.readl_be = spider_readl_be,
	.readq_be = spider_readq_be,
	.readsb = spider_readsb,
	.readsw = spider_readsw,
	.readsl = spider_readsl,
	.memcpy_fromio = spider_memcpy_fromio,
	};

	static int __init spider_pci_workaround_init(void)
	{
	struct pci_controller *phb;

	if (!machine_is(cell))
	return 0;

	/* Find spider bridges. We assume they have been all probed
	* in setup_arch(). If that was to change, we would need to
	* update this code to cope with dynamically added busses
	*/
	list_for_each_entry(phb, &hose_list, list_node) {
	struct device_node *np = phb->arch_data;
	const char *model = of_get_property(np, "model", NULL);

	/* If no model property or name isn't exactly "pci", skip */
	if (model == NULL \|\| strcmp(np->name, "pci"))
	continue;
	/* If model is not "Spider", skip */
	if (strcmp(model, "Spider"))
	continue;
	spider_pci_add_one(phb);
	}

	/* No Spider PCI found, exit */
	if (spider_pci_count == 0)
	return 0;

	/* Setup IO callbacks. We only setup MMIO reads. PIO reads will
	* fallback to MMIO reads (though without a token, thus slower)
	*/
	ppc_pci_io = spider_pci_io;

	/* Setup ioremap callback */
	ppc_md.ioremap = spider_ioremap;

	return 0;
	}
	arch_initcall(spider_pci_workaround_init);